cc: Change RTree::Search to return results, add comments, more tests.

cc/base/rtree_perftest.cc

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "cc/base/lap_timer.h"
 #include "cc/base/rtree.h"
 
 #include "testing/gtest/include/gtest/gtest.h"
 #include "testing/perf/perf_test.h"
 
@@ skipping 32 matching lines @@
         gfx::Rect(-10, -10, 1, 1), gfx::Rect(0, 0, 1000, 1000),
         gfx::Rect(large_query - 2, large_query - 2, 1, 1)};
     size_t query_index = 0;
 
     std::vector<gfx::Rect> rects = BuildRects(rect_count);
     RTree rtree;
     rtree.Build(rects);
 
     timer_.Reset();
     do {
-      std::vector<size_t> results;
-      rtree.Search(queries[query_index], &results);
+      rtree.Search(queries[query_index]);
       query_index = (query_index + 1) % queries.size();
       timer_.NextLap();
     } while (!timer_.HasTimeLimitExpired());
 
     perf_test::PrintResult("rtree_search", "", test_name,
                            timer_.LapsPerSecond(), "runs/s", true);
   }
 
   std::vector<gfx::Rect> BuildRects(int count) {
     std::vector<gfx::Rect> result;
@@ skipping 23 matching lines @@
 
 TEST_F(RTreePerfTest, Search) {
   RunSearchTest("100", 100);
   RunSearchTest("1000", 1000);
   RunSearchTest("10000", 10000);
   RunSearchTest("100000", 100000);
 }
 
 }  // namespace
 }  // namespace cc